Telephone-transformer.



No. 683,954. Patnted Oct. 8, men n. LIEBREICH.

TELEPHONE TRANSFORMER. (Appliclticm filed Nov. 80, 1900..)

(No Model.) 2 Sheets-Sheet I.

rgl .1 5

M ML A x Patented Oct. 8, I901.

H. LIEBREIC-H. TELEPHONE TRANSFORMER.

(Applicniou fund Nov. 80, 1900.\

2 Sheets-Sheet 2.

(No Model.)

UNITED STATES PATENT QFFIGE.

HANS LIEBREICH, OF DETROIT, MICHIGAN, ASSIGNOR TO FREDERICK ROHNERT, OFSAME PLACE.

TELEPHONE-TRANSFORM ER.

SPEGIFIGATION forming part of Letters Patent No. 683,954, dated October8, 1901.

Application filed November 30, 1900. Serial No. 38,199. (No model.)

To all whom it may concern:

Be it known that I, HANS LIEBREICH, a citizen of the United States,residing at Detroit, in the county of Wayne and State of Michigan, haveinvented certain new and useful Improvements in Telephone-Transformers;and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention relates to improvements in apparatus for increasing thesensitiveness of telephone instruments and the power with whichimpulses, tones, or signals are reproduced over the same.

It consists in a mechanism comprising one or more induction-coils havinga primary and secondary winding, cores mounted within the coils andformed of casings filled with comminuted iron filings or dust, and barsconnecting the ends of the cores outside the coils, and means forconnecting the primary winding of the induction-coil with transmitting,instruments and a source of electrical energy and the secondary coilwith receivers.

It further consists in an induction coil made up of primary andsecondary windings, the secondary winding being diminished in resistanceopposite its neutral point, a core for the said coil made up of a hollowcasing, a filling of iron-dust, and short sections of small iron wirescompressed under hydraulic pressure to form a solid mass, barsconnecting the ends of the said cores formed of hollow casings alsofilled with compressed irondust and short iron rods, and means forconnecting the induction-coil with the rod.

It also consists in certain other novel constructions, combinations, andarrangements of parts, as will be hereinafter more fully described andspecifically claimed.

In the accompanying drawings, Figure 1 is a longitudinal central sectionthrough my improved apparatus for increasing the sensitiveness oftelephones. Fig. 2 is a horizontal central section through the same.Fig. 3 is a transverse cross-section through the coils of theinstrument. Fig. 4 is a horizontal central section through a coil havinga modified core connection, and Fig. 5 is a diagrammatic view showingthe manner of connecting the instrument with a telephone-line.

My improved apparatus is designed to be connected up with the receiversand transmitters of a telephone-line, so that it will increase thesensitiveness of the reproductions produced at the receivers.

The invention resides, chiefly, in the construction of an induction-coil1, which is employed as a transformer and is provided with a primarywinding 2 and a secondary winding 3. Vhile I may employ only one suchcoil, I preferably arrange two coils side by side and connect theircores together to form a single instrument. The cores of the said coilsare formed of hollow casings, as 4 4, which are designed to be filled byfinely-coniminuted pieces of soft iron. \Vhile very fine iron-dust isfound to be sui'ficient for this purpose, I preferably form thecore-filling of a series of short sections of iron wire, as 5 5, theinterstices between the same being filled with fine iron-dust and thewhole mass being compressed under hydraulic pressure to form a solidmass. The cores may be connected at their ends by any suitable bars, as6 (3; but I preferably form the said bars in the same manner in whichthe cores are formed namely, in hollow casings 7, filled with smallpieces of iron rods and iron-dust closely packed together. As seen inFig. 5 of the drawings, the primary coils 2 2 are connected with abattery 8 and a receiver 9, while the secondary coil 3 is connected withthe linereceivers. I find in use that when varied impulses are sentthrough the primary windings of the coils by means of the transmittersand the batteries that the vibrations of the particles in the coresincite currents in the secondary windings of high tension, so that theimpulses started at the transmitters are reproduced with loudness anddistinctness at the receivers. I preferably reduce the resistance of thesecondary coils opposite their central or neutral points by diminishingthe winding of the wire at thatpoint and increasing the same graduallyto points opposite their poles. I may also vary the construction of thecoils and their cores without departing from the spirit of theinvention. As seen in Fig. 4 of the drawings, for instance, the coressired, as well as with iron-dust.

10 may be formed of casings larger at their ends than at their centers,the reduction in size being made opposite the neutral points of the saidcores and the cores being filled in this instance with the compressediron rods and dust, as 11. Core pieces or poles, as 12 12, are insertedin the ends of the cores 10 and extend some little distance into thecomminuted iron filling. The pole-pieces 12 12 are preferably connectedwith bars 13 13, which may be made of soft iron, if desired. The cores10 '10 are surrounded by primary windings 14. 14., also diminished insize at their central points,and an outer Winding or secondary coilisplaced outside the primary coil,it being also reduced in thicknessopposite the central point of the coil. This construction of core andcoil, havinglarge ends to form strong poles and reduced central portionsto diminish the resistance, produces induction-coils of great power andlittle resistance. In coils of the construction just described theprimary windings are connected with the receivers and batteries of theline, as above set forth, and the line-wires and the receivers are aloneconnected with the secondary windings. It will thus transpire that onlythe induced impulses of high tension are transmitted to the receiversand powerful and distinct results are delivered at the same.

The principal feature of this invention is the construction of the coreswith the fine particles of soft iron, and in these cores the vib'rations of the molecules or atoms of iron produce the inducedcurrents. in'tlie secondary coils. The construction is simple andyetvery eifective and capable of improving the action oftelephone-line's.

In forming a mixture for the cores of the induction-coils I alsocontemplate mixing the short iron wires with owhen de- In making any oneof the mixtures referred to for the core-filling any suitable adhesivematerial may be mixed with the iron wires or iron-dust to more perfectlyhold the mass together, all within the spirit of the present invention.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. An apparatus for increasing the sensitiveness for telephone systemscomprising a coil having a primary and secondary winding adapted to beconnected up with a telephoneline, a core for the said coil comprisingahollow casing, a compressed mass of finely-comminuted soft iron fillingthe said core for producing induced currents of high tension in thesecondary winding of the said coil, substantially as described.

2. Atransformerfor telephones comprising coils having primary andsecondary windings, cores in the said coils consisting of hollowcasings, compressed fillings of comminuted particles of soft ironforming a solid mass, and means for connecting the primary wires withtransmitters and batteries and the secondary wires with receivers,whereby the receivers will be operated by induced currents, from thesecondary windings, of high tension, substantially as described.

3. Atransformer for telephones,comprising a pair of coils having primaryand secondary windings, cores extending through eachcoil, barsconnecting the ends of the cores, a filling for the cores and theconnecting-bars comprising short iron Wires and iron-dust closely packedtogether,and means for connectingthe primary and secondary coils withthe telephone-line, substantially as described.

4. A transformer for telephones comprising coils having primary andsecondary windings, cores mounted therein having fillings of comminutedpieces of soft iron and iron-dust,

pole-pieces extending into the ends of the said cores, and barsconnecting the said polepieces, substantially as described.

5. A transformer for telephones,com prisin g coils having primary andsecondary windings, which are reduced in size at their'centers oppositetheir neutral points, cores within the said coils also reduced at theirneutral points, fillings of iron-dust in the coils, pole-piecesextending into the cores and bars connecting the same, substantially asdescribed.

6. A transformer for telephones comprising an induction-coil having aprimary and a secondary winding,a hollow core mounted within the same, afilling in the said core, consisting of a compressed mass of soft-ironwires mixed with oxid of iron, and bars connecting the poles of thecores outside the coils, substantially as described.

In testimony whereof I hereunto aflix my signature in presence of twowitnesses.

- HANS LIEBREIOH.

Witnesses:

JOHN L. FLETCHER, CAssELL SEVERANCE.

